The invention relates to a filter apparatus for continuously thickening suspensions in a filter thickener provided with candle-shaped filter elements.
The German Offenlegungsschrift DE-OS No. 27 41 639 discloses a filter thickener including a filter container in which a plurality of collecting pipes are arranged. A plurality of filter elements depends in series from the collecting pipes which are located adjacent to each other on support members and can be individually removed from the filter container.
From the Austrian patent AT-PS No. 211 329, there is known a plant for backwashing of filter candles which are arranged in series. The line conduits to which the filter elements are mounted, are guided horizontally on both sides through the container wall.
The bilateral guidance of the line conduits is, however, rather cumbersome and consequently expensive. In addition to the extensive number of container boreholes, each of the line conduits is provided with two shutoff devices, thereby rendering necessary a plurality of valves and armatures.
Moreover, it is to be noted that all known apparatuses of this kind for thickening suspensions by means of a filter thickener inherit the disadvantage that after termination of a filtration cycle, filter aids have to be added in order to improve the service life of the filter apparatus.